Heretofore, various types of deviated wellbores have been drilled from a primary wellbore. One particular type of deviated wellbore, known as a drainhole wellbore, is drilled from a primary wellbore through a sharp radius of curvature to extend laterally away from the primary wellbore. Normally, although not necessarily, the primary wellbore is essentially vertical and the drainhole, after passing through its sharp radius of curvature extends essentially horizontally away from the primary wellbore out into the producing geologic formation.
Heretofore, commercial drill pipe has been cut in such a fashion as to make it flexible and this drill pipe has been used to pass through the curvature of radius from the primary wellbore to the drainhole for drilling and/or other working in the drainhole. This type of flexible drill pipe is known in the drainhole wellbore art as "wigglies". Drainhole wellbores, the method for drilling same, and wigglies are fully and completely disclosed in U.S. Pat. Nos. 3,349,845 and 3,398,804.